Respiratory Diseases Quiz

Study Notes

Ventilation (V) refers to the movement of air into and out of the lungs.
It involves the rate at which air enters and leaves the lungs.
Ventilation ensures the delivery of oxygen (O2) to the alveoli and removal of carbon dioxide (CO2) from the body.
Two types of ventilation exist: pulmonary and alveolar.

Pulmonary ventilation (RMV) is the process of moving air in and out of the respiratory tract in a given minute during quiet breathing.
It's also known as minute ventilation or respiratory minute volume.
Pulmonary ventilation involves a cyclical process where fresh air enters the lungs, and an equal volume of air leaves them.
Normal pulmonary ventilation is 6 L/minute.
Calculated by multiplying tidal volume (TV) by respiratory rate (RR)
Formula: Pulmonary Ventilation = Tidal volume × Respiratory rate
Example: 500 ml × 12/min = 6000 ml/min

Alveolar ventilation is the amount of air used for gas exchange every minute.
It's different from pulmonary ventilation.
Pulmonary ventilation involves all the air moving in and out of the respiratory tract (6L/min), but not all of that air is used in gas exchange
Alveolar ventilation only accounts for the volume of air exchanged in the alveoli.
The air trapped in the respiratory passage (called dead space) is not used in gas exchange

Extends from the nose up to the terminal bronchiole.
Includes the nose, pharynx, trachea, bronchi, and their branches up to the terminal bronchioles.
These structures are only passages for air movement.
Gas exchange does not occur in these structures

Includes anatomical dead space plus two additional volumes which do not function for gas exchange.
1. Air in the non-functioning alveoli due to respiratory diseases (like damaged alveoli) or dysfunction of the alveolar membrane.
1. Air in alveoli not receiving adequate blood flow (inadequate blood supply).
These two volumes represent wasted ventilation

Perfusion (Q) is the flow of blood through the pulmonary capillaries.
It allows the transport of oxygen (O2) from the alveoli to tissues and the return of carbon dioxide (CO2) to the lungs.
Pulmonary circulation maintains perfusion with low pressure.

Ventilation-perfusion ratio (VA/Q) is the ratio of alveolar ventilation to the amount of blood perfusing the alveoli.
It showcases the relationship between the amount of air entering the alveoli (VA) and the blood flowing through the surrounding capillaries (Q).
Normal value is 0.84.

Under normal conditions, the normal volume of dead space is 150 ml.
Physiological dead space is equivalent to anatomical dead space.
All alveoli function properly, receiving adequate blood flow.
Physiological dead space increases during respiratory diseases affecting pulmonary blood flow or alveoli.